User or human interface devices, such as scroll-wheels, scroll-balls, touch-screens and touchpads, are widely used in a number of applications to interface with and input data into a number of electronic products including personal computers, workstations, personal digital assistants (PDAs), cellular telephones, digital media players and the like.
Scroll-wheels and scroll-balls include mechanical sensors that require openings to be made in the device's enclosure, and thus render the scroll-wheel or scroll-ball and the electronic product are susceptible to failure due to moisture and dirt.
Conventional touch-screens or touch-pads while eliminating the need for an opening into the device's enclosure typically require a large navigation area on the end product, and thus are not suitable in a number of applications including for use with portable or handheld products.